Text

Forwards Draft Evaluation of SEP Topic III-5.A, Effects of Pipe Break on Structures,Sys & Components Inside Containment. Evaluation Will Be Basic Input to Integrated Safety Assessment Unless as-built Facility Differs
	ML17309A170
Person / Time
Site:	Ginna
Issue date:	06/30/1981
From:	Crutchfield D; Office of Nuclear Reactor Regulation
To:	Maier J; ROCHESTER GAS & ELECTRIC CORP.
References
	TASK-03-05.A, TASK-3-5.A, TASK-RR LSO5-81-06-127, LSO5-81-6-127, NUDOCS 8107020346
	Download: ML17309A170 (28)
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A June 30, 1981 E

'I Docket No. 50-244 LS05 06-127 Nr. John E. Naier Vice President Electric and Steam Production Rochester Gas E Electric Corporation 89 East Avenue Rochester, New York 14649

Dear Nr. Maier:

SUBJECT:

SEP TOPIC III<<5.A, EFFECTS OF PIPE BREAK ON STRUCTURES, SYSTEMS AND COMPONENTS INSIDE CONTAINMENT - R. E.

GINNA Enclosed is our draft evaluation of SEP Topic III-.(.A. This assessment compares your facility with the criteria currently used by the regulatory staff for licensing new facilities.

Please inform us ifyour as-built faci'lity differs from the licensing basis assumed in our assessment with-in 30 days of receipt of this 'letter.

This evaluation will be a basic input to the integrated safety assessment for your facility unless you identify changes needed to reflect the as-built conditions at, your facility.

This assessment may be revised in the future if your facility design is changed or if NRC criteria relating to this subject is modified before the integrated assessment is completed.

As noted in the enclosure, there are some items which were not resolved during our review.

Please provide your schedule for resolution within 30 days of receipt of this letter.

In future correspondence regarding this topic, please refer to the topic number in your cover letter.

Sincerely, OR DC fiel d 6+81 AD,$A: DL" GLA'nas 6/)0/81 Dennis N.

Crutchfield,;CQQf'perating Reicto} s Branch No. 4 Division of Licensing

Enclosure:

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" Docket No. 50-244 LS05 Nr-John E. Naier Vice President Electric and Steam Production Rochester Gas 8 Electric Corporation 89 East Avenue Rochester, Ne<< York 14649

Dear Nr. Naker:

SUBJECT:

SEP TOPIC III-S.A, EFFECTS OF PIPE BREAK ON STRUCTURES, SYSTEMS AND COMPONENTS INSIDE CONTAINMENT -

R ~ E. GINNA Enclosed is our draft evaluation of SEP Topic III-S.A.

This assessment coo@ares your facility with the criteria currently used by the regulatory staff for licensing new facilities.

Please inform us if your as-built facility differs from the licensing basis assumed in our assessment with-in 30 days of receipt of this letter.

This evaluation wi'll be a basic input to the integrated safety assessment for your facility unless you identify changes needed to reflect the as-built conditions at your facility.

This assessment may be revised in the future if your facility design is changed or if NRC criteria relating to this subject is modified before the integrated assessment is completed.

As noted in the enclosure, there are some items for which further informa-tion is needed to complete our review.

Please provide your schedule for coryletion within 30 days of receipt of this letter.

In future correspondence regarding this topic, please refer to the topic number in your cover letter.

Sincerely.

Enclosure:

As stated Dennis N. Crutchfield, Chief Operating Reactors Branch No.

5 Division of Licensing

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+~*~4 Docket No. 50-244 LS05-81-06-127 UNITED STATES NUCLEAR REGULATORY COMIVIISSION WASHINGTON, D. C. 20555 June 30, 1981 Mr. John E. Maier Vice President Electric and Steam Production Rochester Gas 8 Electric Corporation 89 East Avenue Rochester, New York 14649

Dear Mr. Maier:

SUBJECT:

SEP TOPIC III-5.A, EFFECTS OF PIPE BREAK ON STRUCTURES, SYSTEMS Af'ID COMPONENTS INSIDE CONTAINMENT - R.

E.

GINNA Enclosed is our draft evaluation of SEP Topic III-5.A. This assessment compares your facility with the criteria currently used by the regulatory staff for licensing new facilities.

Please inform us if your as-built facility differs from the licensing basis assumed in our assessment with-in 30 days of receipt of this letter.

This evaluation will be a basic input to the integrated safety assessment for your facility unless you identify changes needed to reflect the as-built conditions at your facility.

This assessment may be revised in the future if your facility design is changed or if NRC criteria relating to this subject is modified before the integrated assessment is completed.

As noted in the enclosure, there are some items which were not resolved during our review.

Please provide your schedule for resolution within 30.days of receipt of this letter.

In future correspondence regarding this topic, please refer to the topic number in your cover letter.

Sincerely, Dennis M. Crutchfield Chic'f Operating Reactors Branch No. ~

Division of Licensing

Enclosure:

As stated cc w/enclosure:

See next page

fear. John E. tlaier CC Harry H. Voigt, Esquire

LeBoeuf, Lamb, Leiby and HacRae 1333 New Hampshire

Avenue, N-W.

Suite 1100 Washington, D. C.

20036 Hr. tlichael Slade 12 Trailwood Circle Rochester, New York 14618 Ezra Bialik Assistant Attorney General Environmental Protection Bureau New York State Department of Law 2 World Trade Center New York, New York 10047 J effrey Cohen

'New York State Energy Office Swan Street Building Core 1,

Second Floor Empire State Plaza

Albany, New York 12223 Director, Technical Development Programs

'tate of New York Energy Office Agency Building 2 Empire State Plaza

'Albany, New York 12223 Rochester Public Library 115 South Avenue Rochester, New York 14604 Supervisor of the Town of Ontario 107 Ridge Road West

Ontario, New York 14519 Resident Inspector R. E. Ginna Plant c/o U. S.

NRC 1503 Lake Road

Ontario, New York 14519 Hr. Thomas B. Cochran Natural Resources Defense Council, Inc.

1725 I Street, N.

W.

Suite 600 Washington, D. C.

20006 U. S. Environmental Protection Agency Region II Office ATTN:

EIS COORDINATOR 26 Federal Plaza New York, New York 10007 Herbert Grossman, Esq.,

Chairman Atomic Safety and Licensing Board U. S. Nuclear Regulatory Comnission Washington, D. C.

20555 Dr. Richard F. Cole Atomic Safety and Licensing Board U. S. Nuclear Regulatory Commission Washington, D. C.

20555 Dr.

Emmeth A. Luebke Atomic Safety and Licensing Board U. S. Nuclear Regulatory Coranission Washington, D. C.

20555

SEP TOPIC III-5.A EFFECTS OF PIPE BREAK ON STRUCTURES, SYSTEMS AND AND COMPONENTS INSIDE CONTAINMENT R.

E.

GINNA

TABLE OF CONTENTS I.

INTRODUCTION II.

REVIEW CRITERIA III.-

RELATED SAFETY TOPICS AND INTERFACES IV.

REVI EW GUIDELINES V.

DISCUSSION A.

BACKGROUND B.

ANALYSIS ASSUMPTIONS C.

SAFETY RELATED EQUIPMENT VI.

EVALUATION A.

ASSUMPTIOHS AHD CRITERIA B.

INTERACTION STUDIES VII.

CONCLUSIONS VIII. REFERENCES

I.

INTRODUCTION The safety objective of Systematic Evaluation Program (SEP) Topic III-S.A,."Effects of Pipe Break on Structures, Systems and Components Inside Containment," is to assure that pipe breaks would not cause the loss of needed function of "safety-related"

systems, structures and components and to assure that the plant can be safely shutdown in the event of such breaks.

The needed functions of "safety-related" systems are those functions required to mitigate the effects of the pipe break and safely shutdown the reactor plant.

I I.

REVIEW CRITERIA The current criteria for review of pipe breaks inside containment are contained in Standard Review Plan 3.6.2, "Determination of Break Locations and Dynamic Effects Associated with the Postulated Rupture of Piping,"

including its attached Branch Technical Position, Nechanical Engineering Branch 3-1 (BTP l<EB 3-1).

III.

Background

In a letter dated February 9, 1979 (Reference 2),

RGEE submitted a list of high energy lines i nside contai nment.

Representatives of the NRC and RG8E staff met at the Ginna site on March 13 and 14, 1979, to discuss the analyses done by the licensee on this topic.

As a result of this meeting, the licensee submitted'n September 12, 1979 a report (Reference

3) on the effects of breaks in these lines on safety-related equipment.

This review. utilized the effects-oriented approach for the Qgh energy line breaks analyzed.

In this approach, breaks were postulated at any location along the line, and were chosen to produce the greatest jet impingement or pipe whip loadings on essential equipment.

Also, the assumed plane of motion was that which produced the most adverse effects unless otherwise justified.

B.

Analysis Assumptions The following assumptions were made by the licensee:

1.

High energy fluid systems are systems with operating temperature greater than 200'F or operating pressure greater than 275 psi g.

In accordance with Branch Technical Position (BTP)

MEB 3-1, breaks are not postulated in pipi ng of systems that qualify as high energy systems for only short operational periods (i.e.',

less than 2X of the time the system operates as

a. moderate energy system).

Pipes less than one inch (1") in diameter were also eliminated in accordance with Regulatory Guide 1.46.

2.

Pipe, of a given section modulus will not cause a loss of func-tion in pipe of equal or larger section modulus. as a result of pipe whip or jet impingement.

3.

Pipe whip can only occur in the section of pipe which is attached to a sustained high energy source.

Credit is taken for all closed or automatically closed valves (e.g.,

check valves) in the piping section that could terminate flow.

4.

The jet impingement force (calculated to be less than 200 pounds) due to breaks in the 2" diameter lines fed by the positive displacement charging pumps will not impair function-ingg of equipment.

5.

In addition to the equipment affected by the break, a single independent failure of an active component inside containment is considered.

C.

Safety-Related Equipment Safety-related equipment includes systems needed to mitigate the effects of the line breaks and to bring the reactor to safe shut-down.

Breaks inside containment generally result in or have. the same effect as loss of coolant accidents or steam/feed line breaks.

Engineered safety features are required to mitigate these breaks.

Other breaks (such as accumulator line breaks) do not result in a loss of inventory or energy from the reactor coolant system and thus require only normal safe shutdown systems such as CVCS.

Systems that are all or partially inside containment are:

Safety Injection (SI) - two trains one to each cold leg, no active components inside containment Low Pressure Safety Injection (LPSI) - two trains which pump water. to the injection nozzles on the vessel through mo'tor-operated valves (MOVS) 852A and B, which rest change position on receipt of a safety injection signal Accumulators - directed to each cold leg, no active components Containment Spray - two trains to spray headers in containment, no active components inside containment Containment Fan Coolers and Service Water - four fan coolers which must operate to provide cooling; service water has no active components inside containment Sump Recirculation.- two lines from the sump to Emergency Core Cooling System (ECCS)

pumps, no active components inside containment Residual Heat Removal

- one drop line, one return line, each with two MOVs

Chemical and Volume Control (CVCS) Charging and Letdown - two

- physically separated charging paths Standby Auxiliary Feedwater System ties into main feedwater

lines, no active components inside containment; auxiliary feedwater system is totally outside containment Essential Instrumentation - pressurizer

pressure, steam generator level.

VI'.

EVALUATION A.

Assum tions and Criteria As discussed earlier, lines separated from an energy reservoir by a check valve were not assumed to have~sufficient energy to whip or produce jets.

For long runs of large piping, the energy stored within the pipe volume from the break to the valve could be suffi-cient to form a jet.

For Ginna,

however, the only pipes for which the check valve separation is utilized to limit interactions are 2"

pipes, so this effect is not expected to be significant.

The staff concurs. that use of the pipe section modulus is an appropriate measure of relative strength of pipes.

The licensee has assumed that a pipe of larger section modulus will break a pipe of smaller section

modulus, but a smaller section modulus was not considered to affect a larger section modulus.

In accordance with staff positions transmitted on January 4, 1980 (Reference 4), the effects of jet impingement loads should be considered and evaluated regardless of the magnitudes of the section modulus of impinged and postulated broken pipes.

Therefore, the licensee should perform additional'valuations.

of the effects of jet impingement on equipment and piping.

An acceptable jet model is described in Standard Review Plan Section 3.6.2.

Single failures of active components inside containment, such as the fan coolers or LPSI valves were considered by -the licensee.

Loss of offsi4e power was not specifically addressed in this study, but the staff has included consideration of the consequences in its

'eview.

In the safety injection and accumulator

systems, a loss of offsite power,'

single failure and a broken injection line would not prevent injection flow into the other loop.

For the con-tainment spray

system, a loss of offsite power, single failure of a diesel and a rupture of one spray line could reduce containment heat removal capability below the minirmm assumed in the LOCA analysis.

Thus, a break that could affect a containment spray line should be further considered to see if the remaining systems are adequate.

B.

Interaction Studies For each of the postulated break locations, the licensee evaluated the effects on the essential equipment.

In addition, th'e effects on other impacted equipment were considered to ensure that failure of such equipment would not exacerbate the break effects.

The results of these interaction studies are summarized in Table 1.

As shown in the Table, several of the streaks would be confined within one of the loop compartments, would not affect the other trai n of safety injection, or the low pressure safety injection system, and therefore, would not prevent safe shutdown.

Most breaks in loop compartments do not affect safety-related electrical equipment since this equipment is not located inside the 'compartments.

For other lines, a check valve separates the break location from the energy reservoir of the reactor, so no pipe whip is generated.

A high energy line is assumed to break an impacted line of smaller section modulus.

If this impacted line is also a high energy line, the potential dynamic effects of that break must be concurrently considered.

The check and isolation valves located close to the reactor.connection on most of the high energy lines assure that even if a line is broken by the initiating pipe break, there is insufficient energy to produce other effects from the second break.

Such a situation arises with the accumulator line (from tank skirt to loop compartment wall).

Breaks in this line can affect the Residual Heat Removal (RHR) outlet line.

This line is itself a high energy line within the loop compartment, but is not a high energy line outside the compartment due to the two normallymlosed isolation valves.

4 Within loop compartments or within the pressurizer compartment, the potential exists for high energy lines to.impact other high energy lines, such as the RHR in line impacting a charging line.

However, in general, the minirmin engineered safety features (ESF) needed to mitigate these breaks are physically separated from the break and are thus unaffected.

Breaks in the primary loop of reactor coolant system (RCS) were not addressed by the licensee in this study on the basis that USI A-2 (Asymmetric Blowdown Loads on Reactor Primary Coolant System) and related generic topical reports cover the effects.

The staff notes that the A-2 focus is on the loadings on vessel internals and component

supports, but not of direct impingement or whip effects.

However, resolution of the A-2 issue for plants within the Westinghouse owners

group, such as Ginna,is presently expected to utilize the "leak-before-break" concept.

If "leak-before-break" is accepted for this piping, no further review of pipe whip effects will be required to resolve SEP Topic III-5.A for piping within the scope of the A-2 review.

Jet effects from the postulated opening size would still have to be addressed.

If the outcome of A-2 is different, the licensee mJst address the Qnamic effects of breaks in RCS piping using the SEP methodology.

Since the decision on A-2 is anticipatqd by August 1981, we find it acceptable to defer further considerations of RCS breaks until that time.

Breaks that do not fall i nto the above categories were considered separately as shown i n the Table.

Based on the interaction studies, several locations have been i dentified with potentially unacceptable consequences for which further evaluation is necessary.

The licensee has indicated that for some breaks, a mechanistic approach based on breaks at locations of high stress may be used if acceptable consequences cannot be shown using the effects-oriented approach.

This evaluation would use stresses being calculated under the seismic upgrade program.

A mechanistic approach can be used provided that the applicable guidelines are followed, i.e., that breaks are postulated at ter'minal ends and at.locations of high stress, with two intermediate locations, as a minimum (See Reference 1).

If these analyses still result in unacceptable consequences, other possible fixes are installation of jet shiel'ds and pipe restraints and relocation of vulnerable equipment.

The staff,- however, feels that the relocation of equipment or other modifications to mitigate the con-sequences of some pipe breaks may be impractical due to physical plant configurations.

Therefore, for specific locations where relocation of equipment or other modifications to mitigate consequences of pipe breaks are demonstrated by the licensee to be impractical, fracture

mechanics evaluation of the piping should be performed to ascertain if unstable rupture could occur as the result of normal and faulted loads being applied'to large undetected flaws-This evaluation should contain estimates of the margins against fracture that exist for the postulated flaw(s) and the loading conditions as well as estimate of slot sizes for assessing the effects, of jets, if appropriate.

The staff will review the evaluations on a case-by-case basis.

In the near future, guidance regarding postulated flaw size and configura-tion, margins and methodology will be provided.

If fracture mechanics evaluation confirms that the piping system of interest has adequate margin against unstable fracture, augmented in-service inspection and local leak detection should be utilized to assure service-induced flaws are detected.

VII.

CONCLUSIONS The staff has reviewed the layout drawings, analyses and other information provided by the licensee.

In addition, the staff toured representative locations on June 1-2, 1981 in the Ginna containment to observe the pipe configurations and proximity to safety related equipment.

Based on these

reviews, we conclude that the licensee has satisfactorily addressed the pipe whip and jet effects of high energy line breaks inside containment and has demonstrated an adequate level of protection subject to resolution of the following:

1.

Clarify the assumptions used in the evaluation of the effects of postulated pipe breaks with respect to the jet model and the analyses of pipe motions caused by the dynamic effects of postulate'd pipe breaks.

If the assumptions were different from those described in Sections V.A and VI.A, justify the assumptions used or demonstrate that the consequences of the possible new interactions are acceptable.

2.

A break in either a main steam or main feedwater line could impact the containment wall.

The licensee must demonstrate that the pipe whip will not result in penetration of the containment wall. If some loss of,containment function occurs an assessment must be provided of the consequences.

3.

At some locations in the "B" main steam line, a break could impact support columns for the containment crane structure and possibly cause the crane to fall.

The licensee must ensure that the dynamic effects of a mai n steam line break will not cause the crane to fall or demonstrate that breaks need not be postulated i n those locations based on a mechanistic evaluation.

A break in the accumulator line between the tank skirt and the loop compartment walls could interact with the LPSI lines (result-ing in a LOCA) and with the RHR outlet line-A break could also impact containment spray or safety injection lines.

Breaks in this line could also interact with cables for instrumentation circuits, the LPSI valve controls and fan coolers.

The licensee vast demonstrate that the consequences of this scenario are acceptable, provide restraints and protection or demonstrate that breaks need not be postulated in this area based on a mechanistic evaluation.

Breaks in the 10" pressurizer surge line could result in a large LOCA.

Pipe whip from breaks in this line could impact some of the following:

a LPSI valve, one SI-train, a containment spray'ine and the sump.

Damage to one LPSI valve, and a single (i ndependent) failure of the other LPSI valve would result in loss of the low pressure ECCS flow which is needed to qitigate a 10" -line break.

Also, damage to the sump could affect long-term post-LOCA core cooling.

Therefore, the licensee rmst provide shields and/or restraints to protect essential equipment from,the dynamic effects (pipe whip and jet impingement) or demonstrate that breaks need not be postulated in these areas based on a mechanistic evaluation.

A break in the "A." loop pressurizer. spray line could affect reach rods for the sump valves 851A and B.

The licensee rmst ensure that adequate protection is provided for the reach rods so that a spray line break does not restrict sump flow below the required value.

The letdown line outside the "B" compartment is near the pressurizer pressure cables.

The licensee must provide protection for the cables from the dynamic effects of a letdown line break or demonstrate. that breaks in this line will not prevent. accident mitigation and safe shutdown.

The steam generator blowdown lines are on the same elevation as the fan coolers.

Although the lines are restrained by the surrounding service water piping so that pipe whip-is not of concern, protection of the fan cooler from a jet has not been established.

In addition, cables for some of the steam generator level transmitters, pressurizer instrumentation and fan coolers are near the blowdown line.

The licensee must either provide protection for essential equipment from the dynamic effects or show that the break effects will not prevent safe shutdown and mitigation of the break.

9.

Our acceptance of the consequences of breaks within loop compart-ments is predicated on the assumption that the dynamic effects of pipe breaks are contained by the compartment walls.

-Therefore, the licensee should provide appropriate references to supporting analyses for cooqartment wall integrity.

10.

As discussed in Section VI.B, conclusions on the adequacy of the review of pipe breaks in the primary RCS loop are deferred pending issuance of the USI A-2 position.

VIII.

REFERENCES 1.

Letter from D. Eisenhut (NRC) to L. D. White (RGSE),

dated September 7, 1978.

2.

Letter from L. D. White (RGRE) to D. Ziemagn (NRC), dated February 9, 1979.

3.

Letter from L. D. White (RG8E) to D. Ziemann (NRC), dated September 12, 1979.

4.

Letter from D. Ziemann (NRC) to L. D. White (RGKE), dated January 4, 1980' ABBREVIATIONS USED IN THE TABLE CS

- Containment Spray CV

- Check Valve ESF

- Engineered Safety Features (Safety Injection Containment Spray, etc. )

HX

- Heat Exchanger LOCA

- Loss of Coolant Accident LPSI

- Low Pressure Safety Injecti on t<OV

- Hotor Operated Valve PORV

- Power Operated Relief Valve RCP

- Reactor Coolant Pump RHR

, -. Residual Heat Removal SI Safety Injection

'W

- Service Water

TABLE 1:

PIPE BREAK INTERACTIONS INSIDE CONTAINMENT Pioing Run Location Interactions with Mechanical Equip-ment It Other Piping Consequences nteractions with '.

Electrical Equip-ment Consequences LPSI line from valves to vessel nozzles Outside loop compart-LPSI valve 852A or B

ments 236-242'levations 4" LOCA pipe break plus single failure of otht r LPSI valve leads to loss of all LPSI flow.

How-ever, for this size

break, LPSI is not neede RHR is not affected-Acceptable Cables for LPSI valve 852A or B

'" LOCA, pipe break plus single failure leads to loss of all LPSI flow; but LPSI flow not required for this break size-Acceptable Alternate charging (from valve 383A to RCS Loop "A" cold leg) downstream valve normally closed In loop A compartment Piping within A compartment 246'levation Small LOCA, minimum ESF unaffected-Acceptable None No ESF cables or instruments in the compartment-Acceptable Letdown ("B" leg to penetra-tion)

Starts within B compartment (248')

then is outside compartment to penetration (238'levation)

Loop "B" SI piping (in compart-ment)

Small LOCA, minimum ESF unaffected.-

Acceptable.

Loop "A" SI (outside containment)

Same section modulus-Acceptable LPSI, Cont.

spray (outside compart Larger section modulus-ment)

Acceptable Pressurizer pressure cables LPSI valve cables Failure could affect initiation of safety injection-Potentially un-Acceptable.

Not required for this size break-Acceptable Charging (from valve 295 to "8" cold leg)

(from valve 393 to "B" hot leg)

Within loop B compart-Piping within loop B compartment ment 243'-246'leva-tion Small LOCA, minimum ESF unaffected

-Accept-able None No ESF cabl es in compartment - Accept able From check valve to penetrations Exits B compartment to None penetration 239'-246'o sustained high energy None source - Acceptable No sustained high energy source-cceptable

Piping Run Location Interactions with Hechanical Equip-ment E Other Piping Consequences nteractions with Electrical Equip-ment Consequences RCP seal - in (pump back to the check valves)

Outboard of check.

valve Within loop compart-ments (A and 8) 250'levation Outside loop compart-ment Piping in Loop compartment None All piping has at least as big section modulus; minimum ESF unaffected Acceptable No sustained energy source - Acceptable None None No ESF electrical quipment inside compartment - Accept able No sustained high nergy source-Acceptable RHR - out (RCS to MOV)

Within "A" compart-ment 237-244'leva-tion Piping in loop "A" compartment LOCA minimum ESF unaffected - Acceptable None No ESF electrical quipment inside the ompartment-cceptable RHR - in (MOV to RCS)

Within "B" compart-ment 242-244'leva-tion Piping in loop "B" compartment Same as RHR - out None Same as RHR - out Accumulator/SI (RCS to CV 867A, B)

Within loop compart-ments 246-249'leva-tion Piping within the loop compartment

( IlAll or IIBII)

Same as RHR - out None arne as RHR out Accumulator (Tank skirt to loop com-partment walls)

IIAII IIB II Outside compartment 237-250'levation RHR - out containment spray LPSI lines to vessel nozzles SI discharge line LPSI lines to vessel nozzle Can generate LOCA (from LPSI line) also lose use of RHR, with single failure of other LPSI, have no low pressure cool ing - Potentially un-acceptable LOCA could be caused by LPSI break; minimum ESF unaffected, LPSI flow not needed - Acceptable Pressurizer pressure cir-cuits - steam generator "A" level circuits Cable for LPSI HOVs 852A and B fan coolers 1B and lc LPSI valve 852B ca6le; fan cooler 1D cable otenti ally unaccept ble otenti ally unaccept ble if LOCA is enerated ontainment response

's potentially. un-cceptable if LOCA

's generated by PSI line break

4

Piping Run Location Interactions with Mechanical Equip-ment Im Other Piping Consequences nteractsons with ',

Electrical Equip-ment Consequences Accumulator branch lines - instrument taps Vertical, along side accumulator tank (237'r up)

None Line not directly connec ed to RCS; no blowdown; normal shutdown-Acceptable Pressurizer and steam generator instruments circuits Could affect monitor ing of plant condi-tions -. Potentially unacceptable Cables for. LPSI valves

~

Not needed for this or sump valves break - Acceptable Drain (to MOV)

SI discharge lines (from CV downstream of MOV, to accumula-tor line)

Extends.5'rom accumulator tank near basement floor Near shield wall out-side compartments naive within 10'f accumulator line intersection 246-249'levation None LPSI line seal injection (A)

Larger section modulus

- Acceptable See drain lines

'None Pressurizer and steam generator instrumentation circuits Located well below electrical cables Acceptable Potenti al ly unaccept able Steam generator blowdown (generator to penetration)

Passes through loop compartment above intermediate floor to pen'etration 255'levation 2 Fan coolers Service water lines Blowdown.pipe won't whip; r estrained by SW piping.

Larger section modulus-Acceptable 2 Fan coolers steam generator level trans-mitter Pressurizel'nstruments otentially unaccept bl e Standby auxiliary feedwater (generator to CV)

Above operating floor 288'levation Main steam/feed water lines Larger section modulus-Acceptable None ll ESF equipment

's below the operat-:

ing floor -Accept-ble Main feedwater (penetration to generator "A")

283't generator to 305'levation at penetration (mostly above loop compart-ent)

Containment wall Main steam line Standby auxiliary feedwater Potenti al ly unacceptable Larger section modulus acceptable Minimum ESF unaffected-Acceptable Same as above

Piping Run Location Interactions with Mechanical Equip-ment 5 Other Piping Consequences nteractions with Electrical Equip-ment Consequences Main feedwater

("B" generator) 283't generator to 289't penetration As "A" main feed sare as

."enerator "A" NONE same as generator IIAll Main steam

("A" generator to penetration)

Above operating floor Containment wall 314'levation Main feedwater line Potenti al ly unacceptable Minimum ESF unaffected-Acceptable None Main steam

(".B" generator to

. penetration)

Above operating floor 315't generator 305't penetration Same as "A"

Containment crane support structure Same as "A" Potentially unacceptable Same as "A" Same as "A" Auxiliary spray (CV 297 to RCS)

(CV 297 to Regen.

HX)

Within pressurizer compartment 270'o 241'utside pressurizer compartment Other piping in the compartment None Minimum ESF unaffected Acceptable No sustained energy source - Acceptable None None No ESF equipment in the compartment-Acceptable No sustained high energy source-Acceptable Pressurizer surge (loop "B" hot leg to pressurizer)

Within "B" loop com-partment; to pressuri zer through hole in support slab 240'-

246'levation LPSI line to 852B valve SI to loop "A" Containment spray line Single failure of other LPSI valve results in no LPSI; 10" break needs LPSI - Potentially un-acceptable Still have loop "B" SI-Acceptable Have redundant line, but a single failure could r duce heat removal capa-bility - Potentially unacceptable Cables for sump valves

851A, B

Normall open motor-operated valves not required to change position, breakers outside containment-Acceptable

Piping Run Location Interactions with Mechanical Equip-ment 8 Other Piping Consequences nteractsons with '.,

Electrical Equip-ment Consequences Pressurizer surge (loop "B" hot leg to pressurizer)

(cont)

Note:

Affected equi ment depends on brea location; not all interactions can occ simultaneously Sump Hot leg SI to loop "B" Auxiliary Charging Potentially unacceptable Sti 1 1 have 1 oop "A" SI-Acceptable Not needed for. safe shut-down Acceptable Pressurizer spray "A" cold Leg to pressurizer "B" cold leg to pressurizer Through "A" compart-ment across outside compartment to press-urizer compartment 240'p to 274'levationat press-urizer Inside loop compart-ment,and pressurizer compartment 246'p to 274'rain "A" SI (Accumulator, LPSI, CS)

Reach rods for'ump valves

851A, B

Train "B" SI Small LOCA minimum ESF unaffected-.

Acceptable Potentially unacceptable if flow from sump is restricted due to mechanical damage Small LOCA, minimum ESF unaffected

- Acceptable

'Cables for LPSI valves

852A, B

Cables for sump valnes 851 A, B

Not required for this size break-Acceptable Same as for surge line PORV (Pressurizer to Valves)

Inside pressurizer compartment 274'levation Other piping in the compartment

-Small LOCA, minimum.ESF unaffected - Acceptable None No ESF equipment in pressurizer compartment-Accept-able Pressurizer safety valves (pressurizer to valves)

Inside pressurizer compartment 274'levation None

~

V 4

ML17309A170

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ML17309A170

Text

Dear Nr. Maier:

SUBJECT:

Enclosure:

Dear Nr. Naker:

SUBJECT:

Enclosure:

Dear Mr. Maier:

SUBJECT:

Enclosure:

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